Necticut telephone



'June 5, 1923.

S. D; LIVINGSTON CURRENT REGULATOR FOR IGNITION SYSTEMS Filed Jan. 28, 1920 Patented June 5, 1923.

um'rao STANLEY D; LIVINGSTON, OF MERIDEN, CONNECTICUT, ASSIGNOR TO THE CON- NECTICUT TELEPHONE & ELECTRIC COMPANY, INCORPORATED, OF 'MERI DEN, CONNECTICUT, A CORPORATION OF CONNECTICUT. I

CURRENT REGULATOR FOR IGNITION SYSTEMS.

Application filed January as, 1920. Serial No. 354,596.

internal combustion motors for automobiles and the like.

The main object is to so regulate the current as to obtain satisfactory ignition not only when the motor is running at low speed but also at high speed.

In battery ignition systems of the closed circuit type the flow of current through the primary circuit for a given applied electromotive force is controlled by-two factors;

namely, the resistance of the primary circuit and the inductance of the ignition coil.

This primary circuit resistance is usually such as to give a flow of current that will give satisfactory ignition. Improved ignition is usually obtained if this'current is increased, but at the same time, the sparking in the igniter points. becomes excessive, resulting in' short life in service.

The inductance of the primary circuit is a controlling factor in the energy that can be stored in the coil. As this factor is increased, the heat of the secondary spark is increased (otherfactors such as electromo' tive force, igniter speed, etc. being constant).

As this inductance is increased, the speed at which the coil will give satisfactory igni tion is reduced, as this inductance controls the time required to allow the current to reach its maximum value in the primary 4 circuit. With a normal coil, especially one that gives a hot spark at low igniter speed,

say 3,000 sparks er minute, it will be found that with the igniter operating to give 10,000 sparks per minute the current in the primary circult will be only approximately of the value obtained at low igniter speed. It is this decrease of current flow with increasing igniter speed that decreases the eflectiveness of battery ignition at high 50 engine speed. a

In th device described below this 'difliculty is overcome to a" marked extent. The principle of operation is as follows; at low igniter speed, sufiicient current flows to de flect a thermostat sufliciently to insert a reas sistance in the primary circuit. The coil and igniter are designed to operate at low speed with this resistance in circuit. If the igniter speed is increased the current flow is reduced, due to the inductance of the coil, and the deflection of the thermostat decreased until this resistance is short-circuited, resulting in increasing the flow of current in the primary. The characteristics of the thermostat are such as to short circuit the resistance before the current has decreased suficiently to result in poor ignition and vice versa to insert this resistance in circuit when the igniter speed is reduced, before the current has increased to a value that will damage the coil or igniter.

In practice this regulator should have two elements. The resistance that is added to the circuit when the thermostat deflects is used to operate another element and cause it to deflect away from the primary element. Otherwise the primary element would return, due to decrease in current encountered when the-resistance is inserted. Also, as igniter, speed increases, the primary element returns and short circuits the resistance, causing the other elements to cool and follow the deflection of the primary element, this deflection being produced by the increased current, Fluttering at the resistance contacts is overcome in the manner described in the above two instances, al- .though it is understood that the action of the auxiliary thermostat is only effective at the point in the speed range where it is deas signed to have the regulator operate. For

large current changes, such as are controlled by speed and coil inductance, the primary 4 element alone is effective.

One method of utilizing the above principle is to make it art of a unit that is used to automatica y disconnectjhe ignition coil from the battery should the ignition switch be left on with the engine stopped and the igniter contacts closed. This unit is described more fully in a separate application of Charles E. Stahl, 322,- 107, filed September 6, 1919. The thermo-- stat of the automatic switch is used as theauxiliary element of the regulator, and theresistance of the automaticswitch is the resistance that is inserted in the primary circuit by operation of the regulator.

Fig. 1, is a diagram showing the circuits of the regulator when the motor is running is suitably constructed to be included in the circuit with the source of current and the coil and to operate automatically.

In the particular form shown there is a base 10 of insulating material which supports all of the metallic parts of the re ulator. The primary arm 11 formed of imetallic or thermostatic metal, is secured to this base and has wound around it a heating coil 12, one end of which is secured to the arm and the other end of which is secured to a terminal 13, the intermediate portion being insulated from the arm. .14 is a resistance wound around the member 15 and having one end electrically connected to the base of arm 11v and the other end secured to the member 15, the intermediate portion'being insulated from the member 15." Connected to the member 15 is another arm 16 arranged intermediate 11 and 15. Arms 11 and 16 are provided with contacts which are adapted to move inopening and closing the circuits- In--theiparticular form herein shown as one embodiment of the invention, the member 15 is also a thermostatic arm forming a part of an automatic cut-out. The post 17 carries aspring-pressedplunger 18 which in turn has a transversely adjustable contact pin. 19 on which the tip of the arm 15 normally rests when the parts are in operation. Arm 16 is also preferably of thermostatic metal.

The arm 11 is so constructed that when the speed of the motor passes above the lower limit, the free end of the arm moves to the right as viewed in 'the drawings. The arm 15 is so constructed that the heat from the coil 14 tends to move the arm 15 to the right and with it the a'rm 16 which is also heated.

At low speed operation the current passes from the terminal T3 through the heating coil 12 to the arm 11, thence to the resistance 14, to the arm 15, contact pin 19 and post 17. When the speed increases and the ourrent decreases due to induction, the arm 11 moves to the right to complete the contact with arm 16, and thus short circuit the resistance 14 and increase the current for op eration at speeds above the low limit. When the speed ,of the enginedecreases, the

the arm 15 will be gradually heated by the resistance coil 14 so as to disengage the tip of the arm 15 from the pin 19, whereupon the circuit will be immediately opened by the action of the spring-pressed plunger. By a proper proportioning of the resistance coils 12 and 14 and the arms 11, 15 and 16 the regulator may be designed to operate at any particular motor speed desired. It should be understood of course that if the regulator is designed to short circuit the resistance 14 when a speed of say-20()O R. P. M. is reached, the short circuit will not be discontinued at the same speed when the motor is slowing up but the short circuit will continue until the motor has reached some such speed as say 1800 R. P. M.

I claim 1. In a motor ignition system, the combination of an automatic switch, a resisttzuce, and thermostatic means including a heating coil for automatically short circuiting the resistance when the speed of the motor increases above a predetermined limit.

2. In a motor ignition system, the combination of a thermostatic arm, a coil for heat ing said arm, a resistance in series with said heating means at motor speeds below the predetermined limit and a contact adapted to co-act with said arm and short circuit said resistance when the motor speed increases above said limit.

3. In an ignition system, a coil, an igliiter,

a source of current, a resistance in series with the igniter and thermostatic means for automatically short circuiting the resistance when the igniter speed reaches a certain limit, and the current falls below a certain limit.

4. In a motor ignition system, a source of current, a resistance in circuit therewith and thermostatic means for automatically short circuiting said resistance when the speed of the motor reaches a certain limit, and the curent falls below a certain limit.

5. In an ignition system, a circuit, a sparking device therein, means for directing current through said circuit intermittently to cause correspondingly intermittent sparking at the sparking device, a variable resistance 6. Motor ignition apparatus including two thermostatic arms, a heating resistance for each arm, an intermediate arm carried by one of said thermostatlc arms and in conadjacent said resistance'and heated nee-mic tact with the other arm at certain motor speeds and automatically separated therefrom at certain lower speeds.

7 Motor ignition apparatus including two thermostatic arms, a heating coil on each arm and means for automatically short circuitin one coil when the current decreases.

8. otor ignition apparatus including two thermostatic arms, a heating coil on eac arm, means for automatically short circuiting one coil when the current decreases and means for automatically opening the circuit when the current is continuous beyond a certain limit.

9. Motor ignition apparatus including two thermostatic arms, a heating coil on each arm and an intermediate arm for automatically short circuiting one coil when the current decreases.

10. Motor ignition apparatus including a thermostatic arm, a heating coil thereon, a resistance connected to said coil, and means for short circuiting saidresistance automatically when the current decreases.

11. Motor ignition apparatus including a thermostatic arm, a heating coil thereon, a resistance connected to said coil and an arm thereby for short circuiting said resistance automatically when the current decreases.

12. Motor ignition apparatus including two resistance elements in series and thermostatic means for automatically short circuiting one resistance when the current decreases I automatically terminating the short circuit when the current increases above a certain amount.

13. Motor ignition apparatus two resistance elements in series, automatically short circuitin when the, current decreases including means for one resistance low a certain minimum and for automatically terminating the short circuit when the current increases above a certain amount andmeans for automatically opening the circuit through the motor is running slowly,

both resistances upon a prolonged abnormal flow of current through one of said resistances.

14. Motor ignition apparatus comprising two resistance coils normally in series with the primary of the ignition apparatus when and thermostatic means influenced by one of said coils for automatically cutting out one of said coils when the motor reaches a predetermined s eed.

15. otor ignition apparatus-comprisin two resistance coils normally in-series witl i the primary of the ignition apparatus when the motor is running slowly,;and thermostatically controlled means for automatically cutting out one of saidcoils whenthe motor reaches a predetermined speed, and an autobelow a certain minimum and for adapted to be cut out.

16. Motor ignition apparatus including a stationary contact, a movable contact and a resistance coil associated with said movable contact and movable therewith and normally in series with the primary of the ignition coil at low engine speeds and adapted to move said movable contact to break the circuit under abnormal conditions of the circuit, and thermostatically controlled means in series wi h said coil atlow speeds and adapted to short circuit said coil when the motorreahes a predetermined speed and the current falls below a certain limit.

17. In a motor ignition apparatus, two

resistance coils normally in series'with the primary of the ignition apparatus when the motor is running slowly, thermostatic means influenced by one of said coils for automatically short circuiting one ofsaid resistance coils when the motor reaches a predetermined speed, and an automatic switch controlled by one of said coils to be actuated upon a prolonged. abnormal flow of current throu h said last mentioned coil. 1

' 18. n motor ignition apparatus, two resistance coils normally in circuit with the primary of the ignition apparatus when the motor is running at slow speed, thermostatic means influenced by one of said coils for automatically short circuitingone of said resistance coils when the motor reaches a predetermined speed, and an automatic switch influenced by one of said coils and adapted to break the circuit through said coils upon a prolonged abnormal flow of current through one of said coils.

19. In a motor ignition system, an automatic switch, two thermostatic arms, a resistance coil for each of said arms, a contact arm carried by and movable with one of said first-mentioned arms and adapted to contact with the other, one or said resistance coils being short circuited when the contact arm is in contact with one of said thermostatic arms, one oil said arms serving to release said automatic switch upon an abnormal fiow of current through the resist- 'ance coil of said last-mentioned arm.

20. In a motor ignition system, two therother and short circuit one of said resistances upon a decrease of current flow through said coils. STANLEY D. LIVINGSTON. 

